Not normally a factor with a top shot.
Your shoulders could be pointing well right or well left at address. This puts the bottom of the swing in the wrong place.
Look for a large deviation from the norm. A driver's ball position should be around the front heel, moving progressively farther back until the ball is near the middle of the stance with short irons (photo).
The club may be deviating from its gentle arc on the backswing, tracking a path that's either too much inside or too much outside. Keep your posture constant without raising up during the backswing.
Don't try to lift the ball into the air by pulling your arms up through impact. Check to make sure the circle of your swing is in the right place by making practice swings in which you try to hit the ground slightly after the ball. (See Hit Down, Dammit! for more about the importance of striking the ball with a descending blow on iron shots.)